A new study has discovered that the mᴀssive Kasta tomb at Amphipolis, northern Greece, which is believed to have been commissioned by Alexander the Great in honor of his closest companion, Hephaestion, was deliberately aligned with the sun to create a dramatic illumination effect on the winter solstice.

3D representation of the structure of the Kasta Tomb. Credit: Magikos Fakos / CC BY-SA 4.0

Published in the Nexus Network Journal, the study was carried out by researcher Demetrius Savvides, who used 3D modeling and astronomical simulation software to investigate the way sunlight enters and moves through the tomb over a year. From his discoveries, on December 21, the winter solstice, sunlight travels through the monument and strikes an extremely precise spot inside the inner funerary chamber, believed to be the location of Hephaestion’s sarcophagus.

Savvides explained that the original orientation of the tomb was altered while it was being built to allow for this solar interaction, underlining its symbolic purpose for rebirth, cosmic order, and eternity.

Discovered in 2012, the Kasta tomb is the largest funeral monument ever discovered in ancient Macedonia. The monument’s grandeur, defined by towering caryatids, intricate staircases, and a stunning mosaic of Persephone’s abduction, has long suggested a connection to figures of great importance. It is widely presumed by scholars to have been built to honor Hephaestion, Alexander’s closest confidant and general, who died in 324 BCE.

Busts of Alexander the Great (left) and Hephaestion (right), at the Getty Villa Museum in Malibu, California. Public domain

Savvides’ findings surpᴀss the winter solstice. His computer simulations showed that throughout a year, sunlight is slowly channeled into the tomb’s plan from the entrance, along corridors and chambers, illuminating architectural elements such as carved sphinxes and mosaics at specific moments. In the autumn, the sun’s rays pᴀss between the sphinxes at the entrance and culminate in full illumination of the burial chamber on the solstice. This symbolic use of light, he argues, was at the center of the spiritual meaning of the tomb, recreating ideas of death, life, and renewal found in ancient Greek belief.

The monument also features iconography representing deities like Persephone, queen of the underworld and goddess of vegetation, and Cybele, the “Mother of the Gods,” further proclaiming its ritual and cosmological significance. Symbols like rosettes and depictions of a ceremonial bull add weight to the idea that the tomb was not just a burial site; rather, it was likely some kind of sacred space of ritual and transition between worlds.

Deer hunt mosaic by Gnosis, late 4th century BCE, Pella. Figures may depict Alexander the Great (right) and Hephaestion (left). Public domain

Interestingly, Savvides speculates that a missing statue may have stood in the inner chamber, so positioned that sunlight would have interacted with it on important dates. He bases this theory on both the empty space in the Persephone mosaic and the gestures of the caryatids, whose upraised hands may have once held a crown or ritual object that was meant to engage with the rays of the sun.

While others have doubted this, Savvides insists that the overall pattern of light was intentional and significant, even if not visible every year because of seasonal cloud cover.

Much more than an example of ancient engineering, the Kasta tomb demonstrates how Hellenistic architecture synthesized astronomy, religious symbolism, and political authority. The use of solar light to emphasize cosmic order was part of a broader tradition in which leaders like Alexander the Great borrowed celestial motifs to reinforce their authority.

More information: Savvides, D. (2025). Illuminating the Kastas Monument Enigma: A Computational Analysis of Solar-Architectural Interaction. Nexus Netw J. doi:10.1007/s00004-025-00817-z